Form Handling and Validation Questions

Covers building and managing user input forms with correct markup and behavior, preventing duplicate submissions, and integrating with backend APIs. Includes client side validation rules such as required fields, format checking, length limits, and controlled versus uncontrolled component patterns in frameworks like React. Emphasizes clear, accessible error messaging and feedback for users, disabled states and loading indicators, input sanitization, and handling form specific edge cases such as empty submissions, partial input, and transient network failures.